Adaptive pre-coding in block data transmission system

The paper presents an adaptive pre-coding algorithm suitable for use in wireless synchronous serial data transmission systems where the channel is slowly varying with time. The pre-coding at the transmitter is such that no signal processing is required at the receiver other than testing the received signal against appropriate thresholds. The data itself is transmitted in the form of blocks of data symbols with different lengths depending on the distortion introduced by the channel. Successive blocks of data are separated either by blocks of training signals or blocks of no signal. The performance of the proposed system is compared with system having fixed block lengths. It is shown that for a given bit error rate the proposed adaptive algorithm achieves considerable higher information transmission rate at relatively reduced complexity of the receiver.